Lake Ndutu and Lake Masek form shallow basins where water accumulates from the nearby areas of slightly higher altitude. The water in both lakes are extremely saline, too saline for human consumption. Lake Ndutu becomes alive with animals during the migration because it is surrounded by the Ndutu woodlands and the Short Grass Plains, which provide ample cover and food.
Located just outside the NCA, to the north-east near Lake Natron, this Volcano, whose Maasai name means 'Mountain of God', has had a major influence on the development of the area. It rises 1830m above the Valley floor. Its ash has been blown westwards onto the plains and helped shape the landscape and ecology. It is the only active volcano in the area, having erupted in 2006 and more recently July 2007.
This remarkable black dune, composed of volcanic ash from Oldonyo Lengai, is being blown slowly westwards across the plains, at the rate of about 17 meters per year. Some 9 meters high and 100 meters long in its curve, it can be found to the north of Oldupai Gorge.
The Gorge is ecologically important because it is a vital nesting site of the Ruppell's Griffon Vulture. The best time to visit Olkarien Gorge is from March to April when the vultures are breeding. This coincides with migration when there is plenty of food available.